Circulating current in 1D Hubbard rings with long-range hopping: Comparison between exact diagonalization method and mean-field approach

Abstract

The interplay between Hubbard interaction, long-range hopping and disorder on persistent current in a mesoscopic one-dimensional conducting ring threaded by a magnetic flux $\varphi$ is analyzed in detail. Two different methods, exact numerical diagonalization and Hartree-Fock mean field theory, are used to obtain numerical results from the many-body Hamiltonian. The current in a disordered ring gets enhanced as a result of electronic correlation and it becomes more significant when contributions from higher order hoppings, even if they are too small compared to nearest-neighbor hopping, are taken into account. Certainly this can be an interesting observation in the era of long-standing controversy between theoretical and experimental results of persistent current amplitudes. Along with these we also find half-flux quantum periodic current for some typical electron fillings and kink-like structures at different magnetic fluxes apart from $\varphi =0$ and $\pm {\varphi }_0/2$. The scaling behavior of current is also discussed for the sake of completeness of our present analysis.

13 pages, 25 figures (Accepted for Publication in Physica E: Low-Dimensional Systems and Nanostructures)

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Cited by in corpus (4)

• Current Correlations in a Quantum Dot Ring: A Role of Quantum Interference
• Magnetic response of non-interacting and interacting electrons in a Möbius strip
• Exact and mean-field analysis of the role of Hubbard interactions on flux driven circular current in a quantum ring
• Probing dielectric breakdown in Mott insulators through current oscillations